New York police and crime lab officials faced tough questions on Thursday about whether a large, unregulated DNA database built in part to solve more gun cases violates the civil rights of the people whose profiles are in it.

Corey Johnson, who chairs the New York City Council’s health committee, said at a joint hearing with the committee on public safety that he was concerned about the rights of people whose DNA winds up in the database. He said that, with no procedures in place to remove DNA profiles from the database without a court order, innocent people are at risk of being erroneously connected to crimes.

“If you’re holding on to their DNA and running it whenever new cases come up, how is that fair?” Johnson asked Chief Medical Examiner Barbara Sampson and the NYPD’s Crime Lab chief, Emanuel Katranakis.

The number of DNA profiles stored by the city has grown dramatically over the last five years. As of July, the Office of the Chief Medical Examiner was storing about 64,000 genetic profiles.

The Trace and WNYC were the first to report details about the size and rapid growth of the database. There are people in it who have never been convicted of a crime, and have no idea that their genetic profiles are routinely checked against evidence collected in criminal investigations.

The DNA in the database comes largely from crime scenes and suspects at a time when it is increasingly easy to obtain a profile from just a few cells left on a water bottle or doorknob.

The parameters and protocols governing the database are not published, nor were they provided to The Trace and WNYC when requested. Johnson asked at the hearing why that information is not readily available. The lab directors said it could be obtained through a public information request.

Katranakis said at the hearing that database hits generate thousands of solid investigative leads a year, and are a major way police nab dangerous criminals. He added that the DNA in the database is also often used to exonerate the innocent, not just convict the guilty.

Marika Meis, the legal director of The Bronx Defenders, a public defenders group, said she’s disturbed by the lab directors’ lack of transparency about whose DNA profiles are in the database.

“Yes, they do routinely put in profiles from someone who is exonerated,” she said. “And they do so automatically, and without clear legislative authority to do so.”

Johnson said his committee will continue its “fact finding” about the database, and may introduce legislation or take other, unspecified action. After hearing from officials, “I still have concerns,” he said.